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HP is aware of the recent vulnerabilities commonly referred to as "Spectre" and "Meltdown". HP has published a security bulletin with patches for these issues and a list of impacted systems. We will continue to update the bulletin as more information becomes available and encourage customers to check the bulletin frequently.

Research and Development on printhead and ink technology produced speed, longer ink life, less user intervention and so on. However, issues surface that affect print quality while using different modes of printing or while using different media. Research and Development, along with manufacturing, is continuously working on these issues to further improve print quality without compromising speed or other advancements.

This document highlights some of the common print quality issues with the HP Business Inkjet 3000 series printer. Workarounds and resolutions are included as appropriate. Some of the issues, which can be clearly shown as an example, are included.

Technical terms or terminology used in this document are explained by means of a glossary.

There are two types of banding, horizontal and vertical. Horizontal banding is in the scan axis (direction of carriage movement) and vertical banding is in the paper axis (direction of paper movement). Horizontal banding is caused by improper line feed and Swath Height Error (SHE) of the printhead. A shorter line feed than intended or a positive SHE (drop shooting outwards), results in dark-line banding. A larger line feed than intended or a negative SHE (drop shooting inwards) results in white-line banding. Vertical banding is caused by bad carriage dynamics (such as carriage vibration.)

1. One solution is to continue printing about 20 to 100 pages (number of pages depends on page coverage) till the drop detection and error-hiding algorithm detects and corrects the problem.

2. If Step 1 is not acceptable, run the ‘clean printhead’ process from the control panel. (Configure device> print quality >clean printhead

Photo Best Hue Shift

BEST mode

Photo media

1. Rerun the color calibration using the control panel of the printer. (Configure device> print quality >color calibration.)

Last Swath Defect

BEST mode

Photo media / Coated media

1. Clean the printhead to try to remove the nozzle defect.

2. Increase the bottom of the form margin.

Special Media Dark Vertical Edge

BEST mode

All special media

1. Use NORMAL mode to print.

Swath Boundary Banding

NORMAL/ QUALITY or FAST mode

Plain paper

1. Rerun linefeed calibration using the printer control panel. (Configure device> print quality >Linefeed calibration). Linefeed calibration for the HP Business Inkjet 3000 series printer will calibrate the printer for line feed accuracy and printhead SHE. The calibration will reduce the occurrence of light banding but may have some level of dark banding.

2. Print in BEST mode.

3. If Step 2 is not acceptable, try changing all color printheads.

Within Swath Hue Shift

NORMAL/ QUALITY or FAST mode

Plain paper

1. Print in BEST mode.

2. If Step 1 is not acceptable, try changing all color printheads.

Banding - Vertical

Photo/Coated/Brochure Media Vertical Banding

BEST modes

Photo/Coated/Brochure

1. New Firmware release, v 62, eliminates most banding.

2. Print in NORMAL mode.

Streaking

Black printhead streaking

NORMAL/ QUALITY or FAST mode

Plain paper

1. Print in BEST quality mode.

2. If Step 1 is not acceptable, try changing the black printhead.

Black printhead transient nozzle out at full blackout

NORMAL/ QUALITY or FAST mode

Plain paper

1. Print in BEST quality mode.

2. If Step 1 is not acceptable, try changing the black printhead.

Smearing

Bottom of Form Black Smearing

NORMAL/ QUALITY or FAST mode

Plain paper

1. Print in BEST mode.

2. Change the bottom margin or move blackout areas away from bottom.

Ragged edges

Severe Theta Z or S-shape printhead alignment

Simplex or the 1st page of the duplex print out

Plain paper

1. Remove the printheads and then reinsert the printheads. This will trigger an Auto Printhead Alignment.

2. If the defect persists, change the printhead set.

Scratches

Transparency scratches

All modes

Premium & Premium Plus Transparency

No known workaround at this time.

Black printhead thermal shut down

Black printhead thermal shut down

NORMAL/ QUALITY or FAST mode

Plain paper

1. If the black ink cartridge is low on ink, replace the black ink cartridge instead of the black printhead and reprint the plot.

2. If the black ink cartridge is not low on ink, open and close the supply access door and printing will resume.

3. If Step 1 and Step 2 do not work, turn off the printer and wait for a couple of minutes before turning on the printer.

When the print swath starts from left to right, cyan ink will be placed before the magenta ink. When the print swath starts from right to left, cyan ink will be placed after the magenta ink. This difference in the two print directions causes the difference in hue. This defect is more visible in HP Business Inkjet 3000 series, plain paper, normal quality printing, as it prints with a 1-pass bi-direction.

Drop shapes and drop placement accuracy can be different when printing in different directions; this can vary the amount of overlap of different color ink droplets resulting in hue shift. Multi-pass printmodes randomize the drop placement and therefore eliminates hue shift.

This is a known inkjet defect. Printheads have a certain level of Swath Height Error (SHE). When the error is negative, a larger line feed than intended (drop shooting inwards), the printed swath is shorter in height than it should be and the effect is light banding. If the error is positive, a shorter line feed than intended (drop shooting outwards), the effect is dark banding.

Printer line feed accuracy is another contributor to swath boundary banding. When the paper is underfed, the result is dark banding. If the paper is overfed, the result is light banding. The printer auto calibrates when a new printhead is detected. This is called linefeed calibration. However, in the case of printheads having mismatched amount of SHE, the algorithm will settle for a dark band.

There are hundreds of nozzles within a printhead and the nozzles have variations in drop weight. There is also variation in their drop placement accuracy. These variations results in hue differences within a swath with 1 pass print mode. The taller printhead height (1 inch vs. ½ inch for products such as the BI 2280) of the HP Business Inkjet 3000 series printheads makes matters worse.

This is a known inkjet defect. Some nozzles will exhibit transient nozzle-out due to an ink plug, external contamination, or other reasons. These transient nozzles will recover after some spitting or printhead servicing. Some nozzles would be out because the printheads are old.

The drop detection and error-hiding algorithm in the printer is designed to detect and hide the missing nozzles. However, drop detection is only triggered at specific intervals. If a nozzle turns bad, the defect will continue to show until the next drop detection takes place.

How often does this occur?

Due to the one-pass printmode of the printer, the defective nozzle is not covered by another pass of printing. Hence the nozzle-out defect is more obvious for the one-pass printmode than multiple-pass printmodes that are found in other products.

In order to achieve higher print quality on special media such as photo paper, a specific area is printed by moving the printhead over the print area more than once. This multipass printmode is effective in hiding some print defects such as those created by nozzle-out and bidirectional hue shift.

The horizontal banding seen on photo printing is created by the same mechanism as those seen on plain paper. This is printer and printhead dependent. Some printer/printhead combinations will have more horizontal banding than the others.

When a printed page is advanced out of the print zone after printing, the trailing edge of the paper may curve up and touch the top wall of the paper path. While printing an area completely black at the bottom of the page, black ink smearing will result at the bottom of the paper. A full black area takes time to dry. This is not an issue for color printing or small areas of black color printing.

The nozzles within a printhead have variation in drop weight. There is also variation in their drop placement accuracy. These variations result in hue differences. The taller printhead height of the HP Business Inkjet 3000 series printhead set (1 inch vs. ½ inch in previous products such as bij2230) makes matters worse. The defect is more obvious in a large area containing neutral tone printing.

In order to keep the media flat on the print zone, the bottom edge of the media must remain in the vacuum zone when printing the last swath. Hence, when printing a plot that has the smallest bottom-of-form margin (~ 6 mm from the paper edge), the paper cannot have micro-step advances without the edge of the paper leaving the vacuum zone. When the last swath is printed for the smallest bottom-of-form margin, the paper is not advanced but the carriage travels to and fro for the multi-pass. The same nozzles will be printing at the same location for all the passes. If there is a nozzle defect on the printhead, the defect is not hidden by other nozzles in other passes, due to this limitation.

How often does it occur?

This will happen whenever there is a nozzle defect on the printhead and when the image is printed right up to the smallest bottom-of-form margin.

This may be a printhead architecture limitation. When the carriage travels the full paper width but only fires a color printhead at the last couple inches of the scan axis, the first few drops from the color printhead will have irregular shape, size and larger drop placement error. This shows up as a darker band at the vertical edge of the color image.

How often does it occur?

It is print content dependent. The defect is more distinctive on coated, brochure and photo media printed using Best mode. It is not distinctive on plain paper printed using Normal mode.

This is an architecture limitation for black no. 12 printheads. When the black printhead is printing a mid-saturation black area, some nozzles do not fire straight. This shows up as light-dark streaking on the plots.

How often does this occur?

Most no. 12 black printheads will have this, but only a small percentage will have severe performance issues.

This is an architecture limitation for no. 12 black printheads. Some printheads have nozzles that are not able to refill in time when printing large areas of full black. This results in white streaks, as the nozzles are not firing ink. If the printhead is not used for a few minutes these nozzles will recover by themselves.

Cockle ribs on the platen (a part inside the printer) scratch the media. The scratches can run page-wide or just a short length. It is obvious on unprinted areas and seen when projected on a reflective (flat) overhead projecter.

How often does it occur?

This is printer dependent. The defect was seen on both new and old (more than 2000 pages printed is old) printers. Pages printed on the same machine will also exhibit varying severity.

To protect the black printhead, the printhead thermal algorithm will trigger a printhead shut down if the printhead temperature exceeds 94C. It has been noticed that when a full black density plot is printed near the end of ink supply in plain paper normal mode, the black printhead nozzle will experience thermal shut down after one swath of starvation.

How often does this occur?

It was observed that less than 10 cases of black printhead exhibited thermal shut down with the recent FW60 released in accelerated testing. The defect occurs only when a full black density plot is printed near the end of the black ink supply. However, this does not happen as a rule whenever these conditions are met.

note:

When this defect occurs, 90% of the time the printer will prompt customers to replace the black printhead instead of the black ink cartridge. This is because black printhead thermal shut down occurs before the IDS triggers an Out Of Ink (OOI). Though the black printhead is perfectly healthy once a new black ink supply is installed, the customers may think that the black printhead is faulty and replace the black printhead instead.

The printable vertical height (y-axis) of the printhead. This measurement is fixed for each print cartridge.

Swath height error

The trajectory error in the paper advance direction from nozzles at both ends of the printhead resulting in larger or smaller swath height.

1-pass print mode

Moving the printhead over a print area just once is called 1–pass print mode.

Multipass printmode

Moving the printhead over a print area more than once is printing in multipass mode. This helps to cover some print defects caused by nozzle-out or bidirectional hue shift.

Cockle ribs on the platen

The platen is a part inside the printer. The ribs in the platen are designed to prevent cockling (curl up or wrinkle) of the paper.

Nozzle

One of the small holes (or orifices) in the orifice plate, through which ink drops are ejected.

Nozzle-out

An image quality defect caused by one or more nozzles failing to deliver ink.

Line feed calibration

Line feed calibration involves adjusting the paper feed for variations in the diameter and run-out of the line feed rollers. Other factors that may be included are paper thickness and swath height error (SHE) of the printheads.
Using the simple relationship of v = r w, (v = linear velocity, r = radius of roller, w = angular velocity), a higher radius of roller in a certain location means that the paper wrapped around the roller at that point would travel more than intended in the linear direction. Similarly, a smaller radius roller causes the paper to move less than intended. A smaller radius hence causes under-feed, which causes overlapped swaths and hence dark-line banding. Larger radius causes overfeed which causes spaced swaths resulting in white-line banding.